Read the direction of the bend: contours whose tip points uphill mark a valley, and contours whose tip points downhill mark a ridge. A stream symbol gives a second check.
This lesson belongs to contours, height and cross-sections. If you first need the basics of steepness, read inferring slope steepness from contour spacing.
What is the rule?
Imagine walking along one contour line. Where it bends sharply, ask which direction the tip of the bend faces.
- Tip towards higher numbers: valley.
- Tip towards lower numbers: ridge or spur.
The reason is that a valley cuts into the hillside, so each contour must swing uphill to go around it. A ridge sticks out, so each contour bulges downhill around it.
Worked example
This is a worked example. On a map, the 40 m contour runs across the page and then bends into a V. The tip of the V points towards the side where the 60 m and 80 m contours lie. A stream symbol runs down the middle of the V.
Step 1: find the direction of the tip. The tip points towards the 60 m and 80 m side, which is higher ground.
Step 2: apply the rule. Tip towards higher numbers means valley.
Step 3: confirm with the stream. The stream symbol sits in the V, and water flows along valley floors, so the answer stands on two pieces of evidence.
Written answer. “The contours bend towards higher ground and a stream lies inside the bend, so this is a valley with the stream flowing along its floor.”
A second stretch on the same map has the 60 m contour bulging towards the side with 40 m and 20 m. Here the tip points towards lower numbers, so it is a ridge or spur, and no stream is shown along its crest.
The mistake: reading the bend backwards
The usual slip is to see a V and answer “valley” straight away, without checking which way the tip points.
| Step | Wrong | Right |
|---|---|---|
| Look at the tip | “It is a V, so valley” | Ask which way the tip points |
| Compare numbers | Skipped | Follow the labels: are they rising or falling? |
| Confirm | Skipped | Check for a stream or a crest |
A V shape alone tells you nothing, because both landforms can make one. The direction is the evidence.
Check yourself
The 100 m contour bends so that its tip points towards the 80 m contour. No stream is marked. Is this a valley or a ridge, and how would you check?
Answer
The tip points towards 80 m, which is lower ground, so this is a ridge or spur.
To check, follow the labelled contours from the bend: the numbers fall in the direction of the tip. A valley would need the numbers to rise towards the tip and usually a stream, so the lack of a stream also supports a ridge.
What to study next
Now use height and distance to draw the side view in drawing a cross-section. Then try the contours practice set.
The contour profile and slope reasoning trainer gives extra drills. For help from a teacher, see online one-to-one Geography tuition.